To say that the world is more and more complex is today considered conventional wisdom. Three overarching factors justify this almost universal perception. First, the communications technology revolution has fostered a formidable compression of space and time. Second, globalization has brought about an unprecedented increase in economic, political, social, and cultural interaction among populations of all regions and countries. Finally, the international scene, which was traditionally dominated by sovereign states, now has to adapt to the rise of new actors, both collective (including international institutions, sub-state governments, transnational corporations, and non-governmental organizations) and individual (including migrants, refugees, tourists, and terrorists). The fundamental changes underway in global politics have quite naturally engendered a vast diversity of reactions among experts. Far from being altogether cacophonic, however, these multiple viewpoints can well be understood as the expression of a coherent dialogue.